This invention relates generally to improvements in the wear quality of the surface of tools and more specifically relates to aqueous solutions and methods for improving the wear resistance of tools exposed to wear incurred in the normal operation of the machinery incorporating the tools.
U.S. Pat. No. 4,710,279 which issued on Dec. 1, 1987 to Norman R. Hozer (hereinafter known as the '279 Patent) disclosed a novel electro-chemical process and an unique electrolytic bath solution for restoring the sharpness of cutting tools. The process disclosed in the '279 Patent is based upon the principal of electro-chemical milling of a tool surface. That is, the tool is immersed into the electrolytic bath solution acting as a conducting electrolyte in which a portion of the surface of the tool is removed. Such electro-chemical milling processes have long been employed to impart smooth surfaces to irregular surfaces such as in deburring. Previous to the issuance of the '279 Patent, resharpening of cutting tools required the machinery incorporating the tools to be shut down while the tools were being reground to approximate the original sharpening edge. Alternatively, replacement tools were used during the refinishing stage, assuming the manufacturer was fortunate enough to have replacement tools on hand at the concomitant extra cost.
The '279 Patent provides for a novel electrolytic bath solution that can be employed to bathe the tools under certain electrolytic conditions that result in resharpened tools which are often superior in wear resistance to the original sharpened tool. Moreover, the time required for the resharpening has been reduced dramatically and, therefore, the downtime and/or the need for additional tools on hand greatly minimized. Finally. the direct costs heretofore attributable to the resharpening process itself has been reduced to a considerable extent through the use of the disclosed method for employing the aqueous solution.
While the electrolytic bath solution and the method disclosed in the Patent '279 have proven to provide a significant advance in the restoration of the sharpness of certain cutting tools and increased life, tools comprised of specific alloys such as, for example, carbide steel base alloys, resist the rapid refinishing of the tools apparently due to polarization occurring on the alloys. Such polarization requires a multiplicity of cycles of moving parts between the electrolytic bath solution and rinse. The need for several depolarization cycles increases the complexity of computer or other programs required for use on automated equipment. This in turn reduced production rates while increasing production costs. Thus, it is desirable that an improvement be made to the aforementioned electrolytic bath solution and method which permits the effective refinishing of such alloys which heretofore have resisted any refinishing.
It has been additionally noted that at certain operating temperatures, the electrolytic bath solution described in Patent '279 may tend to crystallize over time and certain supportive compounds in the solution precipitate out of solution. The occurrence of undesired precipitation is exacerbated when the electrolytic solution is transported during colder periods of the year or where the ambient temperature of the surrounding environment is low. The effect of such crystallization is that the solution may not be at continued optimal effectiveness during operation of the process on tools immersed in the bath, e.g., resharpening the cutting edge of an immersed tool. Therefore, an improvement in the stabilization of the electrolytic bath solution over a wider temperature range would be desirable.